selftests/net: Add TCP-AO ICMPs accept test

Reverse to icmps-discard test: the server accepts ICMPs, using
TCP_AO_CMDF_ACCEPT_ICMP and it is expected to fail under ICMP
flood from client. Test that the default pre-TCP-AO behaviour functions
when TCP_AO_CMDF_ACCEPT_ICMP is set.

Expected output for ipv4 version (in case it receives ICMP_PROT_UNREACH):
> # ./icmps-accept_ipv4
> 1..3
> # 3209[lib/setup.c:166] rand seed 1642623870
> TAP version 13
> # 3209[lib/proc.c:207] Snmp6 Ip6InReceives: 0 => 1
> # 3209[lib/proc.c:207] Snmp6 Ip6InNoRoutes: 0 => 1
> # 3209[lib/proc.c:207] Snmp6 Ip6InOctets: 0 => 76
> # 3209[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 0 => 1
> # 3209[lib/proc.c:207] Tcp InSegs: 3 => 23
> # 3209[lib/proc.c:207] Tcp OutSegs: 2 => 22
> # 3209[lib/proc.c:207] IcmpMsg InType3: 0 => 4
> # 3209[lib/proc.c:207] Icmp InMsgs: 0 => 4
> # 3209[lib/proc.c:207] Icmp InDestUnreachs: 0 => 4
> # 3209[lib/proc.c:207] Ip InReceives: 3 => 27
> # 3209[lib/proc.c:207] Ip InDelivers: 3 => 27
> # 3209[lib/proc.c:207] Ip OutRequests: 2 => 22
> # 3209[lib/proc.c:207] IpExt InOctets: 288 => 3420
> # 3209[lib/proc.c:207] IpExt OutOctets: 124 => 3244
> # 3209[lib/proc.c:207] IpExt InNoECTPkts: 3 => 25
> # 3209[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2
> # 3209[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 20
> # 3209[lib/proc.c:207] TcpExt TCPDelivered: 0 => 19
> # 3209[lib/proc.c:207] TcpExt TCPAOGood: 3 => 23
> ok 1 InDestUnreachs delivered 4
> ok 2 server failed with -92: Protocol not available
> ok 3 TCPAODroppedIcmps counter didn't change: 0 >= 0
> # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

Expected output for ipv6 version (in case it receives ADM_PROHIBITED):
> # ./icmps-accept_ipv6
> 1..3
> # 3277[lib/setup.c:166] rand seed 1642624035
> TAP version 13
> # 3277[lib/proc.c:207] Snmp6 Ip6InReceives: 6 => 31
> # 3277[lib/proc.c:207] Snmp6 Ip6InDelivers: 4 => 29
> # 3277[lib/proc.c:207] Snmp6 Ip6OutRequests: 4 => 24
> # 3277[lib/proc.c:207] Snmp6 Ip6InOctets: 592 => 4492
> # 3277[lib/proc.c:207] Snmp6 Ip6OutOctets: 332 => 3852
> # 3277[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 6 => 31
> # 3277[lib/proc.c:207] Snmp6 Icmp6InMsgs: 1 => 6
> # 3277[lib/proc.c:207] Snmp6 Icmp6InDestUnreachs: 0 => 5
> # 3277[lib/proc.c:207] Snmp6 Icmp6InType1: 0 => 5
> # 3277[lib/proc.c:207] Tcp InSegs: 3 => 23
> # 3277[lib/proc.c:207] Tcp OutSegs: 2 => 22
> # 3277[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2
> # 3277[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 20
> # 3277[lib/proc.c:207] TcpExt TCPDelivered: 0 => 19
> # 3277[lib/proc.c:207] TcpExt TCPAOGood: 3 => 23
> ok 1 Icmp6InDestUnreachs delivered 5
> ok 2 server failed with -13: Permission denied
> ok 3 TCPAODroppedIcmps counter didn't change: 0 >= 0
> # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

With some luck the server may fail with ECONNREFUSED (depending on what
icmp packet was delivered firstly).
For the kernel error handlers see: tab_unreach[] and icmp_err_convert[].

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

selftests/net: Verify that TCP-AO complies with ignoring ICMPs

Hand-crafted ICMP packets are sent to the server, the server checks for
hard/soft errors and fails if any.

Expected output for ipv4 version:
> # ./icmps-discard_ipv4
> 1..3
> # 3164[lib/setup.c:166] rand seed 1642623745
> TAP version 13
> # 3164[lib/proc.c:207] Snmp6 Ip6InReceives: 0 => 1
> # 3164[lib/proc.c:207] Snmp6 Ip6InNoRoutes: 0 => 1
> # 3164[lib/proc.c:207] Snmp6 Ip6InOctets: 0 => 76
> # 3164[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 0 => 1
> # 3164[lib/proc.c:207] Tcp InSegs: 2 => 203
> # 3164[lib/proc.c:207] Tcp OutSegs: 1 => 202
> # 3164[lib/proc.c:207] IcmpMsg InType3: 0 => 543
> # 3164[lib/proc.c:207] Icmp InMsgs: 0 => 543
> # 3164[lib/proc.c:207] Icmp InDestUnreachs: 0 => 543
> # 3164[lib/proc.c:207] Ip InReceives: 2 => 746
> # 3164[lib/proc.c:207] Ip InDelivers: 2 => 746
> # 3164[lib/proc.c:207] Ip OutRequests: 1 => 202
> # 3164[lib/proc.c:207] IpExt InOctets: 132 => 61684
> # 3164[lib/proc.c:207] IpExt OutOctets: 68 => 31324
> # 3164[lib/proc.c:207] IpExt InNoECTPkts: 2 => 744
> # 3164[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2
> # 3164[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 200
> # 3164[lib/proc.c:207] TcpExt TCPDelivered: 0 => 199
> # 3164[lib/proc.c:207] TcpExt TCPAOGood: 2 => 203
> # 3164[lib/proc.c:207] TcpExt TCPAODroppedIcmps: 0 => 541
> ok 1 InDestUnreachs delivered 543
> ok 2 Server survived 20000 bytes of traffic
> ok 3 ICMPs ignored 541
> # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

Expected output for ipv6 version:
> # ./icmps-discard_ipv6
> 1..3
> # 3186[lib/setup.c:166] rand seed 1642623803
> TAP version 13
> # 3186[lib/proc.c:207] Snmp6 Ip6InReceives: 4 => 568
> # 3186[lib/proc.c:207] Snmp6 Ip6InDelivers: 3 => 564
> # 3186[lib/proc.c:207] Snmp6 Ip6OutRequests: 2 => 204
> # 3186[lib/proc.c:207] Snmp6 Ip6InMcastPkts: 1 => 4
> # 3186[lib/proc.c:207] Snmp6 Ip6OutMcastPkts: 0 => 1
> # 3186[lib/proc.c:207] Snmp6 Ip6InOctets: 320 => 70420
> # 3186[lib/proc.c:207] Snmp6 Ip6OutOctets: 160 => 35512
> # 3186[lib/proc.c:207] Snmp6 Ip6InMcastOctets: 72 => 336
> # 3186[lib/proc.c:207] Snmp6 Ip6OutMcastOctets: 0 => 76
> # 3186[lib/proc.c:207] Snmp6 Ip6InNoECTPkts: 4 => 568
> # 3186[lib/proc.c:207] Snmp6 Icmp6InMsgs: 1 => 361
> # 3186[lib/proc.c:207] Snmp6 Icmp6OutMsgs: 1 => 2
> # 3186[lib/proc.c:207] Snmp6 Icmp6InDestUnreachs: 0 => 360
> # 3186[lib/proc.c:207] Snmp6 Icmp6OutMLDv2Reports: 0 => 1
> # 3186[lib/proc.c:207] Snmp6 Icmp6InType1: 0 => 360
> # 3186[lib/proc.c:207] Snmp6 Icmp6OutType143: 0 => 1
> # 3186[lib/proc.c:207] Tcp InSegs: 2 => 203
> # 3186[lib/proc.c:207] Tcp OutSegs: 1 => 202
> # 3186[lib/proc.c:207] TcpExt TCPPureAcks: 1 => 2
> # 3186[lib/proc.c:207] TcpExt TCPOrigDataSent: 0 => 200
> # 3186[lib/proc.c:207] TcpExt TCPDelivered: 0 => 199
> # 3186[lib/proc.c:207] TcpExt TCPAOGood: 2 => 203
> # 3186[lib/proc.c:207] TcpExt TCPAODroppedIcmps: 0 => 360
> ok 1 Icmp6InDestUnreachs delivered 360
> ok 2 Server survived 20000 bytes of traffic
> ok 3 ICMPs ignored 360
> # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>